Uncovering the candidate genes related to sheep body weight using multi-trait genome-wide association analysis

Abstract

In sheep, body weight is an economically important trait. This study sought to map genetic loci related to weaning weight and yearling weight. To this end, a single-trait and multi-trait genome-wide association study (GWAS) was performed using a high-density 600 K single nucleotide polymorphism (SNP) chip. The results showed that 43 and 56 SNPs were significantly associated with weaning weight and yearling weight, respectively. A region associated with both weaning and yearling traits (OARX: 6.74-7.04 Mb) was identified, suggesting that the same genes could play a role in regulating both these traits. This region was found to contain three genes (<i>TBL1X, SHROOM2</i> and <i>GPR143</i>). The most significant SNP was Affx-281066395, located at 6.94 Mb (<i>p</i> = 1.70 × 10^-17), corresponding to the <i>SHROOM2</i> gene. We also identified 93 novel SNPs elated to sheep weight using multi-trait GWAS analysis. A new genomic region (OAR10: 76.04-77.23 Mb) with 22 significant SNPs were discovered. Combining transcriptomic data from multiple tissues and genomic data in sheep, we found the <i>HINT1</i>, <i>ASB11</i> and <i>GPR143</i> genes may involve in sheep body weight. So, multi-omic anlaysis is a valuable strategy identifying candidate genes related to body weight.